AngularJS: Can I use a filter to chunk an array in ng-repeat?

Question

Edit to add a clear question: I have a flat array of some length and I want to put it into a tr/td type view? This might also be in a bootstrap grid or somethin

Answer 1

You can avoid an infinite digest loop by simply memoizing your chunk function. This solves the issue of ng-repeat never finding the proper references and always thinking you are returning new items causing the infinite $digest.

angular.module('filters', []).
  filter('chunk', function () {
​
    function cacheIt(func) {
      var cache = {};
      return function(arg, chunk_size) {
        // if the function has been called with the argument
        // short circuit and use cached value, otherwise call the
        // cached function with the argument and save it to the cache as well then return
        return cache[arg] ? cache[arg] : cache[arg] = func(arg,chunk_size);
      };
    }
    
    // unchanged from your example apart from we are no longer directly returning this   ​
    function chunk(items, chunk_size) {
      var chunks = [];
      if (angular.isArray(items)) {
        if (isNaN(chunk_size))
          chunk_size = 4;
        for (var i = 0; i < items.length; i += chunk_size) {
          chunks.push(items.slice(i, i + chunk_size));
        }
      } else {
        console.log("items is not an array: " + angular.toJson(items));
      }
      return chunks;
    }
​    // now we return the cached or memoized version of our chunk function
    // if you want to use lodash this is really easy since there is already a chunk and memoize function all above code would be removed
    // this return would simply be: return _.memoize(_.chunk);

    return cacheIt(chunk);
  });